Tone quality

Each musical instrument has its own characteristic tone. Individual notes of exactly the same pitch sound different if played on different instruments, and we say the notes have a different tone quality. Terms like 'throaty', 'mellow' and 'full-bodied' are used to describe tone quality. We can often identify someone we know from the tone quality of their voice.

The tone quality of a sound depends on the shape of the wave form. The simplest wave form, a sine wave, is called a pure tone. All other periodic wave forms (complex tones) can be expressed as the sum of a sine wave and some of its harmonics, as we saw in Chapter 6. The number and the relative intensities of the harmonics determine the shape of the wave form. In terms of tone quality, we say that complex tones are combinations of pure tones. The ability to make distinctions between different tones is more enhanced in some people than in others.